Because WLAN systems typically operate in an unlicensed band, it is possible that non-WLAN devices may emit radio signals on the channel currently being used by an on-going WLAN radio connection between a pair of WLAN nodes, such as an access point (AP) communicating with a station (STA). When this interference prevents one or both WLAN receivers from correctly receiving any packets sent by their counterpart, the receivers are said to be “jammed,” or “blind”.
When the level of interference perceived by one or both members of a pair of WLAN nodes impairs the on-going radio-communication, the performance of a radio link established between the nodes may be improved if the communication channel of the radio link is changed to one that experiences a lower level of interference. The speed at which this channel change occurs may have a strong impact on the Quality of Service (QoS) perceived by end users of the communication channel. When the WLAN is used to provide services that require a particular QoS level, it is important for the two WLAN nodes to change the channel as quickly as possible such that the channel change is seamless for the end users.
Currently, there are several conventional mechanisms for performing a seamless channel change. One mechanism allows one WLAN node to convey to its counterpart that it is switching its communication channel. Another more sophisticated hand-shaking mechanism operates by having one node suggest, or request, a channel change and the other node accept or confirm the channel switch suggestion or request. However, such mechanisms require that each WLAN node be able to correctly receive and detect the signaling frame, or frames, sent by its counterpart on the interfered channel as the signaling frame(s) contain the information required to switch the channel. Unfortunately, if interference has jammed the receiver of at least one of two WLAN nodes involved in a radio communication, it is not possible for the two WLAN nodes to switch channels in a seamless manner.
Accordingly, it would be advantageous to provide a method and apparatus that allows jammed devices to blindly and seamlessly switch, or change, channels without the limitations of conventional mechanisms.